The flexibility of a Fine-Granular Scalability (FGS) video encoding enables it to support a wide range of transmission bandwidths as is described in commonly assigned U.S. patent application Ser. No. 09/347,881 entitled “System and Method for Improved Fine Granular Scalable Video Using Base Layer Coding Information” filed on Jul. 6, 1999. An FGS video encoding method is disclosed in commonly assigned U.S. patent application Ser. No. 09/5890,825 entitled “Hybrid Temporal-SNR Fine Granular Scalability Video Coding,” filed on Jun. 9, 2000. In the hybrid temporal-SNR FGS application a video encoding method, and corresponding encoder, is disclosed that is operable to encode and transmit video images with enhanced quality (SNR) FGS encoded form, enhanced temporal (FGST) form and a combined hybrid FGST-SNR FGS form. In the commonly assigned co-pending related application, entitled “Spatial Scalability for Fine Granular Video Encoding”, filed Oct. 11, 2001, which is incorporated by reference herein, methods and corresponding encoders, are disclosed that encode spatially scaled FGS video images. In this method, a video image is downscaled to produce a minimum resolution base layer image that can be subsequently enhanced with an enhancement layer that may provide an improved quality for the base layer, a first enhancement layer that may provide enhanced image resolution and a second enhancement layer that may provide enhanced temporal form for the enhanced image resolution layer.
However, to obtain the benefit of the spatial encoding techniques, proper decoding is necessary. Hence, there is a need for a decoding system that decodes images received in the disclosed FGS spatial scalability encoding format and structure.